Hissing noise from ignition on starting, and causes clock to re-set to 00:00. HELP!!!!!

[cara_essex]

Hi, Me again!!

Been on here a few times recently. STILL having problems with my car, its doing my head in.
Long story very short - it kept loosing revs and cutting out at junctions, mechanic got fault code for Throttle position sensor, but had to replace whole Throttle valve control unit as apparently couldnt get just the sensor for my engine code (AEE)
Anyhow new unit was put in (Ecu Wasnt reset, at the time which I now understand it should have been???) After new unit went in, it was fine literally for 2 days, then revs started going bonkers and are now too high (idles around 1200) and when engine is warm the revs fluctate up and down between 1200-1800. Even when my foot isnt on the accelerator, I can be stopped at a junction, but the revs fluctuate and sometimes I can actually feel the brake pedal go down a tiny bit... almost as if it something to do with pressure?!?? Also sometimes the revs get stuck at 2000rpm... I can drive up my road and slow down for the give way at the end, and despite braking, the revs are vroooming on 2000, then kick back down to 1200ish. Also sometimes when I start the car the revs fly upto about 2500-3000 and VRROOOM for a few seconds, then calm down again.
ALSO, whenever I start the car from cold I turn the key and the ignition sort of makes a 'hissy crunching grindy' noise (I know what I mean, hard to explain!!) and this makes the clock reset to 00:00 and with the weather being so cold its doing this every morning and also sometimes if the cars sat about for a while in the day and got very chilly. Also now have noticed the handbrake light (that used to come on whenever the handbrake was applied) is out even when the brake is on.
I dont know whether this is all linked??? I did think the ignition bit was something to do with damp, as seems worse when its very cold and on frosty mornings... but what would I do to find this out? and where to look??? Would there be anything that water could have got into thats causing this? I done what it said in haynes and sprayed a bit of WD40 near the coil bit and thats not helped, unfortunately thats as far as my mechanical skills take me!!

A mechanics had it for the last few days, hes not getting any fault codes (and also said he reset the ecu in limp mode?) and he cant seem to find any vacuum leaks which is what he thought it was. Also said he checked the inlet manifold bit or something. So bottom line is he cant find the cause. Although he was telling me a story about a vectra which had a similar problem and turned out to need new ECU!!! Could it be that the ignition hissing problem is damp and that this has buggered the ecu? Or are there any magic wands I can wave, in the form of changing a relay etc.

It so annoying and really ******* me off, used to start and run lovely and now sounds like a heap of ****. Gutted. Its not even like I can sell it as it sounds so rough!!

And on top of this, my little boys pram has broken and the tumble dryers up the creek... happy christmas!!!

Thanks lads,
Cara x

[Crasher]

The pedal is going up and down due to varying manifold vacuum, the opposite of pressure but you were on the right track. The ECU needs to be cleared of its learnt values in Adaptation 10 and then the throttle body reset to the ECU in Basic Adjustment mode 04, display group 001, left for 30 seconds to allow the TB to be matched and then the ignition turned off for 30 seconds. There is a possibility of a servo air leak though but your chap says he has checked for this.

[cara_essex]

God that sounds technical! So if I print your post off and tell him to do that he will know what that means i assume? Do you know what I mean by him saying he reset it to limp mode and is this not sufficent?

Also, would the ignition problems be linked to this?

thanks!

[Crasher]

You can't set it to limp mode; it goes there only if it has a faulty sensor. You will need to ask him what fault code machine he has, I only know the procedure for VAG-COM and VW's own systems.

[cara_essex]

Ok thanks.

Apologies for all the daft questions, as you can tell Im just trying to exhaust every possible cause as its been playing up for a couple of months now. It was fine until we went to Devon and done 700 miles in 5 days and it looks like that killed it...ooops. :zx11:


So if my mechanic is capable of doing that then great, but will it fix the ignition hissing aswell or is that yet another problem? Also am I ok to keep driving round with it like this? I dont want to bugger it further and cant see many people helping me this side of christmas!

Thanks

[Crasher]

The TB will hiss if it isn't set up properly but an air leak will also hiss.

[neileg]

ALSO, whenever I start the car from cold I turn the key and the ignition sort of makes a 'hissy crunching grindy' noise (I know what I mean, hard to explain!!) and this makes the clock reset to 00:00 and with the weather being so cold its doing this every morning and also sometimes if the cars sat about for a while in the day and got very chilly. When the battery voltage drops significantly, this will reset the clock and there's a relay that starts to buzz (not sure which one). This happened on my Mk3 and was caused by having almost no water in the battery. A bottle and an half of deionised water and the fault has not reappeared.